Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Show the recessive phenotype, A woman who is heterozygous for a particular ...

A woman who is heterozygous for a particular X-linked recessive trait marries a phenotypically normal man. What percentage of their sons will show the recessive phenotype?

Methods of Cognitive Neuroscience, Methods of Cognitive Neuroscience Give...

Methods of Cognitive Neuroscience Given the vast complexity of human perceptual and cognitive processes on one hand, and that of the human brain on the other (with approximately

Discuss about the function of tear film in short, Discuss about the functio...

Discuss about the function of Tear Film in short. Functions of Tear Film The normal function of the eye is dependent on sufficient supply of tear fluid- a secretion

What is the endocrine function of the placenta, Q. What is the endocrine fu...

Q. What is the endocrine function of the placenta? The placenta besides being the organ through which the exchange of substances between the fetus and the mother is done also h

Biology, excretory organs of different animals from protozoa to mammals

excretory organs of different animals from protozoa to mammals

Define nutritional support management for pancreatic cancer, Define Nutriti...

Define Nutritional Support Management for pancreatic cancer? When there is deficiency of exocrine pancreatic secretions, adequate amounts of pancreatic extract are helpful. It

Exercise- heat production, Exercise- Heat Production During physical ...

Exercise- Heat Production During physical activity heat production by exercise can to some extent substitute for heat generated by shivering. However, exercise also tends to

Define beriefly about the phytoestrogens, Define beriefly about the Phytoes...

Define beriefly about the Phytoestrogens? You may be aware of the surging interest in phytoestrogens (PE) especially in connection with osteoporosis. This section briefly discu

Explain about individual consciousness, Q. Explain about Individual conscio...

Q. Explain about Individual consciousness? The physical brain is not a source of experience as some current neuroscientists now mistakenly believe. While areas of the brain are

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd